Carburetor



June 24, 1930. c, w, MCKMEY' 1,767,599

' CARBURETOR Filed May 27, 1924 2 Sheets-Sheet 1 INVENTOR 19 C ham es WMC Kin/6y June 24, 1930. I c, w. MCKINLEY 1,767,599

GARBURETOR Filed May 27, 1924 2 Sheets-Sheet 2 INVENTOR Charles :42Mc/f/fl/e Patented June 24, 1930 UNITED STATES PATENT orric,

CHARLES W. MCKINLEY, OF TOLEDO, OHIO, ASSIGNOR TO THE 'IILLOTSONMANUFAC- TUBING COMPANY, OF TOLEDO, OHIO, .A CORPORATION OF OHIOCARIBUBETOR Application filed May 27, 1924. Serial No. 716,091.

This invention relates to carburetors and, more particularly, to acarburetor in which a temporarily increased supply of motor fuel isautomatically provided as the throttle valve is opened to accelerate orspeed up the motor.

In the usual types of commercial carburetors, a current of air is drawnthrough the carburetor at a rate controlled by a throttle.

valve, and gasoline or other motor fuel is drawn into the flowingcurrent of air. in proportion to the rate of fiow of the airtherethrough, the quantity of fuel supplied being approximatelyproportional to the quantity of air being drawn through the carburetorand controlled by the position of the throttle valve. As the throttle isopened, the engine supplied with fuel from the carburetor is speeded uthe carburetor being so designed that t e rate of fuel supply is aboutsufficient to supply the demand of the motor at the speeds correspondingto the various throttle openings. As the engine is increasing from alower to a higher speed with the opening of the throttle, 'a somewhatricher mixture is required to bring the engine, and

the mechanism driven therefrom, to the reuired speed than is required tomaintain t em running at the higher speed. Accordingly, a somewhatlarger quantity of fuel is required for a short period of time while theengine is accelerating and speeding up.

An object of the present invention is to fulfill this requirement byautomatically supplying an additional or auxiliary charge of fuel duringthe acceleration of the engine from low to high speed.

Another object of the invention is to provide a carburetor having anadditional or auxiliary fuel supply for acceleration in,

which the feeding of additional fuel is distributed over a period oftime and in which a closing of the throttle within this time will endthe further feeding of this additional fuel.

A further object of the invention is to provide an accelerating fuelsupply responsive to the opening of the throttle, in which the flow offuel to the mixing passage from the opening of the throttle.

nozzle supplied from a Well into which fuel is discharged automaticallyupon the opening of thethrottle. j

' Another object of the invention is to provide an accelerating pumpactuated by the throttle valve and having means for preventing thetrapping of air in the pump.

Further objects, and objects relating to details and economies ofconstruction and operation will definitely appear from the detaileddescription to follow. In one instance, I have accomplished the objectsof my invention by the devices and means described in the followingspecification. My invention is clearly defined and pointed out in theappended claims. A structure constituting a preferred embodiment of myinvention is illustrated in the accompanying drawings forming a part ofthis specification, in which Fi 1 is a plan view of a carburetorembodying one form of my invention,

Fig. 2 is a sectional View of the carbu- V retor, taken on line 22 ofFig. 1,

Fig. 3 is an end view of the carburetor, looking from the left of Fig.2, portions being broken away to show the interior construction, and,

Fig. 4 is a side view, partly in section, of the carburetor, taken online 4-4 of Fig. 1.

In the drawings, the same reference nu-- merals refer to the same partsthroughout the several views, and the sectional views are taken lookingin the direction of the arrows at the ends of the section lines.

In general, my invention consists in providing an accelerating well orreservoir, from which fuel is delivered to the mixing passage to supplythe rich mixture-required for acceleration, said well beingautomatically supplied with a charge of fuel upon I propose to provide apump which is actuated by the throttle valve, or the operatingconnections therefor, and which injects a charge of fuel into suchaccelerating well from which it flows through a jet, nozzle or orificeinto the mixing passage I propose to provide a a well of such dimensionsas to maintain the flow to the mixing passage for a'period after theopening of the throttle, provided the throttle is not closed during thatperiod. I also propose to provide means whereby, if the throttle isclosed before the charge supplied to the accelerating well has been fedto the mixing passage, the balance of said charge is withdrawn from thewell and will not be delivered to the mixing passage. I also propose toprovide a suitable vent to prevent the trapping of air in the pump whenthe pump plunger is raised on the closing of the throttle.

Referring more particularly to the accompanying drawings, the inventionis' illus trated as applied to a standard type of carburetor comprisingthe usual float chamber,

10, from which motor fuel is supplied to a mixing passage or chamber 12having an inlet portion 13 controlled by the choke valve 14, a dischargeopening 15 controlled by a throttle valve 16, and a-Venturi portion 17positioned between the valves 14 and 16. Motor fuel is supplied throughthe adjustable needle valve 18 and a passage or duct 19 to a nozzle 20projecting axially within the Venturi member. The fuel is received in anannular chamber 21 in-the lower portion of the nozzle surrounding an airinlet tube 22 and rises around the tube 22 into a narrow annular passagebetween the tube 22 and a -s aced enclosing tube 23, the upper end of te air tube communicating with said annular passage at the upper end ofthe surrounding tube 23 through openings 24. When the throttle valve 16is open, or partly open, air is drawn through the tube 22 and openings24 into the surrounding tubev23, in which it mingles with the fuelsupplied thereto and passes therewith through open-- ings 25 in the tube23 into an outer sleeve 26 and through the upper open end of the sleeve26 into the Venturi member 17. The quantity of air and fuel drawnthrough the nozzle 20 is governed by the opening of the throttle valve.

When the throttle valve 16 is closed, a

small amount of motor fuel may, however,

be suppliedto the discharge end 15 of the carburetor, supplyingsufficient fuel for slow speeds or for idling. This fuel is suppliedthrough the duct19 to an upright tube 28, the upper end of which opensinto a slow speed jet chamber 30. When the throttle is closed and theengine is turning over, air is drawn through an adjustable inlet 31 intothe chamber 30 and mixes with fuel sucked into the chamber 30 from thetube 28, said mixture being delivered through one or both of theopenings 32 leading from the chamber 30 into the discharge portion 15 ofthe mixing chamber above the throttle valve.

When the throttle valve 16 is opened, the fuel is normally suppliedmainly or entirely through the nozzle 20 and the quantity supplied isproportional to the opening of the throttle. As the throttle is openedto speed up or accelerate the engine, there is a need through the nozzle20 is adjusted. Fuel to meet this additional temporary need and tofacilitate rapid acceleration is supplied by the present invention byfeeding to the mixng chamber a charge of fuel and distributmg thischarge over the period during which the additional power is required.

v To supply this additional charge, a quantity of fuel is permitted toflow from the float chamber 10 through a narrow duct 33, Fig. 4, into apump chamber 34 and fill the chamber 34 up to the bottom face of aplunger 35 movable vertically therein. The plunger 35 is urged upwardlyby means of a spring 36 confined between the lower face of the plungerand a plug 37 closing the lower end .of the pump chamber. The upward anddownward movement of the plunger 35 is limited, and its positioncontrolled, by means of a leverarm 38, rigidly mounted on a shaft 39, onwhich the throttle valve 16 1s mounted, and having an arm 40 at rightangles, against which the upper end of the lever arm 38 is so mounted onthe shaft 39 that it is in its uppermost position when the valve 16 isclosed and that it has forced the plunger 35 to its lowermost position,against the action of the spring 36, when the valve 1s 1n. its positionof greatest opening, the plunger being forced downwardly in directrelatlon to the position of the throttle valve 16.

When the plunger is forced downwardly with an openin movement of thethrottle 16, a small portion of the fuel in the chamber 34 is forcedbackthrough the openin 33 1nto the float chamber 10, but a muc larger quantty is forced through a larger opening 42 into a well 43 extendingupwardly from the level of the opening 42, parallel with the pumpchamber 34. The well 43 is provided at its upper end with an opening 44to the atmosphere which permits the escape of air as the fuel is forced7 chamber 12 at a level slightly above the normal fuel level.

When the throttle valve, 16, is closed, the pump chamber 34 remainsfilled with fuel up to the lower face of the lunger 35 and the well 43is filled u to t e normal fuel level which is below t e nozzle 46, nofuel being drawn into the suction chamber through this passage. When,however, the throttle valve 16 is moved towards open position, theplunger 35 is depressed by, the lever arm 38 and fuel is forced from thepump chamber, 34, into the well 43 raising the level of fuel in thiswell above the level of the nozzle 46,a distance proportional to themovement of the valve 16 and the associated movement .of the plunger 35.The fuel above the level of the nozzle, 46, then. flows through thenozzle into the mixing chamber, supplying the additional'fuel requiredfor speedy and effective acceleration and distributing its supply over asuflicient period of time to permit its effective utilization.

When the throttle valve 16 is moved towards closed position, the end ofthe lever arm 38 is raised proportionately and the plunger 35 forcedupwardly by the spring 36, creating a suction which draws fuel from thewell 43 and, at a slower rate, from the float chamber 10. If the closingof the throttle follows immediately upon its opening and before all ofthe additional fuel has passed from the well 43 through the nozzle 46into the mixing chamber, the level ofthe fuel will fall below the levelof.the nozzle, 46, and the supply of this fuel to the mixing chamberwill be cut off. If sufiicient fuel is withdrawn from the well to lowerits level below the normal fuel level, fuel will flow into the plungerchamber and well through the openings 33 and 42 until the level isrestored.

It will be noted that the well, 43 is open to the atmosphere through thevent, 44. This prevents the suction 1n the Venturi becoming efl'ectivethrough the nozzle, 46, to raise the fuel in well, 43, and draw it intothe mixing chamber through said nozzle. This prevents the discharge offuel through said nozzle during the normal operation of the engine.

The closing movement of the throttle may, at times, be so extensive andrapid as to draw air through the opening 44, well 43 and opening 42into-the ump chamber 34, and to trap such air be ow the plunger. This isobjectionable as it causes irregular operation of the acceleratingdevice. To avoid this occurrence, which would interfere with theoperation'of the carburetor, a narrow air vent duct 47 is provided inthe plunger 35 leading from the pump chamber to the atmosphere,-throughwhich any air sucked into the plunger chamber would be permitted toescape as the fuel'rises in the chamber 34 when the throttle is closed.The duct 47 is so small and long that practically no fuel would beforced through .it to the atmosphere and the open end of this duct isclosed by the wall of the pump chamber as soon as the throttle hasbeenopened a slight extent.

My present invention thus provides a means by which the demand for atemporary additional supply of fuel on the opening of the throttle valveis met and this additional supply of fuel is distributed through asufficient period of time to permit its effective utilization. In thisrespect, my invention is a decided improvement over devices in which anaccelerating pump injects an auxiliary charge of fuel directly into themixing assage when the throttle valve is opened. uch devices provide anover-rich mixture at the instant of acceleration instead of spreadingthis charge over a eriod of time. Furthermore, by means 0 my invention,the wasting of fuel is prevented because, if the throttle .valve ismoved toward closed position after having been opened, the auxiliarycharge is withdrawn from the well and returned to the fuel supplychamber.

As changes of construction may be made within the scope of my invention,I desire that all matter contained in the above description or shown inthe accompanying drawings shall be interpreted as illustrative and notina limiting sense.

Having thus described my invention, what I claim as new and useful anddesire to secure by Letters Patent is:

1. A carburetor comprising a mixing passage, a fuel supply chamber, athrottle valve, a well having a discharge opening to said passage, aplunger chamber having a small opening from said fuel supply chamber andi a larger opening to said distributing well, a plunger in said plungerchamber, a spring confined between the bottom of said plunger and thebottom of the plunger chamber, said plunger having an air vent passageleading fromsaid plunger chamber to the atmosphere closed by the wall ofthe chamber as the plunger is depressed, and means for depressing saidplunger in said chamber against the pressure of said spring as saidthrottle valve is moved towards open position.

2. A carburetor comprising a mixing passage, a fuel supply chamber, athrottle valve, a well having a discharge opening to said passage abovethe normal fuel level and open to the atmosphere at its upper end, aplunger chamber having a small opening from saidfuel supply chamber anda larger opening to said well, a plunger iirsaid lunger chamber having avent leading rom said plunger chamber to the atmosphere' closed as theplunger is depressed,

and means controlled by said throttle valve to move said plunger in andout of said plunger chamber as said valve moves towards open and closedpositions, respectively.

3. A carburetor comprising a mixing passage, a throttle valve therein,means for supplying fuel andair to said passage, a pump for deliveringan auxiliary charge of fuel-to said passage comprising a plungerchamber, a plunger actuated by opening movement of the throttle valve,and means including an opening in said plunger for permitting the escapeof air from said chamber when the throttle valve is in closed position,said last mentioned means being closed by the movement of said plunger.

4. A carburetor comprising a mixing passage including a Venturi tube; athrottle valve; a well having a discharge opening at the restrictedportion of said Venturi tube; a plunger chamber having an unobstructedpassage of larger dimensions to 7 said well and a passage of smallerdimenvalve; a well having a discharge sions to a source of fuel; aplunger in said plunger chamber; means actuated by said throttle valvefor forcing said plunger into said plunger chamber as said throttlevalve is moved in an opening direction; means including an opening insaid plunger for permitting the escape of air from said chamber andadapted to be closed by the wall of the chamber as said plunger 1sdepressed; and means for withdrawing said plunger as said throttlevalveis moved to a closing direction.

5. A carburetor comprising a mixing passage; a fuel supply chamber; athrottle valve; a well having a discharge opening to said passage; aplunger chamber having an opening from said fuel supply chamber and anopening to said distr1buting well; a plunger in said plunger chamber;means for depressing said plunger in said chamber as said throttle valveis moved towards open position, said plunger having an air vent passageto the atmosphere adapted to be closed by the wall of the chamber as theplunger is depressed.

6. A carburetor comprising a mixing passage; a fuel supply chamber; athrottle opening to said passage above the normal uel level and'open tothe atmosphere at its upper end; a plunger chamber having an openingfrom said fuel supply chamber and an opening to said well; a plunger insaid plunger chamber having a vent to the atmosphere adapted to beclosed as the plunger isdepressed; and means controlled by said throttlevalve to move said plunger in and out of said plunger chamber as saidvalve moves towards open and closed positions, respectively. i

7. A carburetor comprising a mixing passage between the plunger chamberand well forming an unobstructed conduit to the well discharge passage,said plunger having an air vent passage ada ted to be closed by the wallof the cham er as the plunger is depressed.

In testimony whereof, I aiiix my signa ture.

CHARLES W. MCKINLEY.

